1. Field of the Invention
The present invention relates to footwear and an insole pad to be laid inside of the footwear, and more particularly, to a structure of the footwear and the insole pad thereof which prevents deformation of a foot by supporting the outward shift of the weight rested on the foot so that a walking posture is well maintained and the shape of the footwear is retained.
2. Description of the Related Art
Three arches on the sole of the foot, known as the three loading arches, function as springs, which makes it possible to move in every direction. The three arches include a plantar arch, an outside arch and a crossing arch at the front of the foot.
The arches discussed above are constituted by twenty-six bones reinforced by muscles and ligaments; however, since these are not firm, the muscles and the ligaments become fatigued and the arches start falling after standing for a long time.
In conjunction with the falling of the arches, the spring efficiency deteriorates, which results in a deterioration in the functions of the foot.
The human foot, sometimes called "the second heart", is composed of a five-layered musculative and blood vessels flow in the midst of the muscles. The blood therefore is pumped up by the contractile muscle movement upon walking and is returned to the heart.
Thus it is desirable to prevent fallen arches caused by resting one's weight on one's foot for a long time and to provide a means for assisting the natural blood circulation system.
FIG. 10 shows a structure of an insole for a conventional shoe 1 and FIG. 11 shows a structure of an insole pad 3 lying on the insole 2 in the shoe 1, in which the entire surface of the insole 2 or the insole pad 3 is flat, or an extrusion 4 is provided at the plantar arch alone to thicken the insole 2 or the insole pad 3.
As shown in FIG. 12, when walking, the weight rested on the foot tends to shift from an outside part (a) to an outside front part in the direction shown by an arrow (b).
The insole 2 employed in the conventional shoe 1 or the insole pad 3 laid on the insole 2 has no ability to support the shift in weight described above. As a result, as shown in FIGs. 10 and 11, the weight shift is supported by an instep strap 5 positioned at the outside of the shoe 1, which leads to a disadvantage of deformation of the shoe caused by the expansion of the instep strap 5 while wearing the shoe.
Further, a force directed to the outside is directed through the entire foot, and can cause bowleggedness.
Bowleggedness can occur particularly significantly among children whose skeletal structures of feet have not yet been completed, not to mention adults whose skeletal structures have been completed.